The effect of phosphorothioated antisense oligodeoxynucleotide (AS ODN) against the μ-opioid receptor () on mRNA level in the periaqueductal gray (PAG) of rat brain was investigated. The mRNA levels at 3, 6, 12, 24, 48 and 72 h after AS ODN microinjection into the PAG were determined by reverse transcriptase-polymerase chain reaction. The mRNA level was significantly decreased only at 12 h after the injection of 10 μg AS ODN. When 10 μg AS ODN was given three times at the interval of 48 h, mRNA levels were significantly decreased at 6, 12 and 24 h after the last injection of the AS ODN. However, mRNA levels were not significantly changed by three injections at 48-h interval of sense ODN or AS ODNs against δ- and κ-opioid receptors, although the two latter AS ODNs significantly reduced the respective targeted mRNA levels. In conclusion, the present results show that the selective decrease in mRNA is at least one reason why the reported diminished effects of agonists are produced in animals pretreated with AS ODN, although they could be produced through several mechanisms in which mRNA level does not change.

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   Introduction: µ-opioid receptor () internalization is caused by (DAMGO) and etorphine, but not by morphine in vitro and in vivo. internalization caused by fentanyl is demonstrated only in vitro. The relationship between internalization and analgesic effect caused by fentanyl has not been studied. In addition, the role of internalization caused by opioid agonists in the analgesic effect in vivo has not been well established. In the present study, therefore, we examined whether fentanyl causes internalization in vivo or not and also studied the relationship between internalization and analgesic effect of opioid agonists.
   Methods: The protocol was approved by our animal research and use committee. Male Sprague-Dawley rats weighing 300–330 g were implanted with intrathecal catheters at the level of L4–5. Tail flick test was performed at 30 min after intrathecal administration of morphine, DAMGO, fentanyl, or saline. Immediately after the test, rats were perfused and the spinal cord was removed. distribution was assessed by immunohistochemical staining of in the dorsal horn neurons.
   Results: The opioid agonists exerted analgesic effect assessed by tail flick test at 30 min after injection. In morphine treated rats, no internalization was observed in the laminae I and II neurons of the spinal cord, as was seen with saline. DAMGO caused internalization in almost all of the neurons expressing . Though fentanyl also produced internalization in the laminae I and II neurons, the internalization was observed in approximately half of the neurons expressing , and the distribution of internalized was different from that induced by DAMGO.
   Conclusion: Intrathecally administered fentanyl caused internalization in the rat spinal dorsal horn neurons. distribution showed different patterns depending on opioid agonists used. These results suggest that the internalization does not seem to be involved in analgesic effect produced by opioid agonist.

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This study sought to re-examine the effects of oral reading ability (ORA) and English ability (EA) on metacognition of oral reading () for Japanese senior high school students. Mivasako (2002) surveyed the students' (n = 120) with a questionnaire and extracted four factors with fifty-one items relevant to them, and showed that their had a significant relationshzp with their ORA and E.A. However, the research did not reveal how their would be different depending on their ORA and E.A, which was the purpose of the present study. In this study, the participants ' was compared between the upper and lower groups of ORA and E.A. The results showed: (a) the upper-ORA group had significantly higher means of than the lower group mainly in Factor I (perceptions on what you can do or strategies you can use in reading aloud); (b) the upper-EA group had significantly higher means of than the lower group mainly in Factors I and IV (perceptions on performing reading-aloud); and (c) E.A. was a significant predictor of in Factors I, II (perceptions on effective strategies in reading aloud) and IV for the upper- and lower-ORA groups, but ORA significantly predicted only in a few items for the E.A. groups.

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The evaluation of morphine hydrochloride () hollow type suppository was carried out by a comparison between rectal and intravenous administrations of in rabbits.The hollow type suppository containing three doses of (1mg/kg, 3mg/kg, 10mg/kg) was used for the rectal administration, and the aqueous solution of (20mg/ml) was used for the intravenous administration (3mg/kg).The serum concentration of was measured with gas chromatography-mass spectrometer by selected ion monitoring method.The absorption constant of from suppository had dose-dependent characteristics, although the peak serum concentrations (1mg/kg;38.8ng/ml, 3mg/kg;61.9ng/ml, 10mg/kg;137.1ng/ml) were reached within 0.4 hours, respectively The area under the curve of serum concentration (AUC) after rectal administration were compaired with the AUC after intravenous administration.The bioavailability (AUC_rectl/AUC_iv×Dose_iv/Dose_rectal×100) were 90%(1mg/kg), 62%(3mg/kg) and 53%(10mg/kg), respectively.These data suggested that the absorption of had dose-dependency. We used hollow type supporitory of for the pain control of patients with cancer for 6 years.It was required to administer every 4-6 hours for pain control.Thus, it was concluded that hollow type suppository could be useful for the pain control of patients with cancer, especially for the patients who were not able to ingest the oral preparations and the patients who need individual dosage adjustment.

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In fission yeast, the conserved proteins, MO25/Pmo25, GC kinase/Nak1, Furry/2, NDR kinase/Orb6, and Mob2, constitute the morphogenesis Orb6 network (). Previously we showed that Pmo25 functions as an upstream component of and that it plays a connecting role between the septation initiation network (SIN) and . Here we establish a Pmo25-associated kinase assay and show that the activity is dependent on Nak1/ and Sid1/SIN.

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To demonstrate the difference in the action mechanisms of morphine (), pentobarbital (Pent) and ethanol (EtOH), comparative studies on the inhibitory effect on the electrical stimulation (ES)-evoked contractions of isolated mouse vas deferens (MVD) were undertaken. All the drugs inhibited the ES-evoked contractions of MVD preparations in a concentration-dependent manner, however, the effects were completely different among 3 drugs in the preparations after incubation in the medium containing each drug and also after acute or chronic treatment with the drugs. The differences among 3 drugs are as follows : 1) The in vitro incubation with , but not with Pent and EtOH developed tolerance. 2) MVD from and EtOH tolerant animals were also tolerant to the inhibitory effect of and EtOH in vitro, respectively. 3) K⁺ and Ca²⁺ stimulated the contractions of MVD and the effect was enhanced further after incubation in . 4) The administration of and Pent dose-dependently enhanced the effect of K⁺ and Ca²⁺, but this effect of was lost following repeated injections. 5) No cross tolerance was developed among 3 drugs in the inhibitory effect following in vitro incubation or in vivo treatment. Thus, the effects of in vitro incubation with , Pent and EtOH, and acute or chronic administration of the drugs on the response of isolated MVD preparations are different from each other suggesting the difference in the underlying mechanisms of the drugs.

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morphine()連投期間は10～11日間とし，その投与量は漸増法に従って増量し，延髄巨大細胞網様核(NRGC)破壊ラットの耐性および依存形成能について検討した．耐性形成はtail pinch法による鎮痛作用を，依存形成は連続投与期間中の体重，体温，血漿corticosterone(Pcs)値および副腎重量の日内変動，ならびに禁断時の体重，Pcs値，血漿ACTH値および副腎重量を指標とした．コントロール痙痛閾値は，連投またはNRGC破壊の影響を受けなかった．連投前におけるNRGC destructedラット(破壊群)の鎮痛は，sham operatedラット(対照群)のそれに比して抑制された．連投1日目初回の連投量(20mg/kg)による鎮痛は，対照群，破壊群共に投与30分後から最大測定時間(10秒)を示し，120分後もなお持続し，非常に強力であった，連投4日目および8日目の対照群における鎮痛は，検定量がそれぞれ40mg/kgおよび80mg/kgと増量されたが，連投前の(5mg/kg)鎮痛と同程度あるいはそれよりも弱いものであり，対照群における耐性形成は明らかであった，連投4日目および8日目の破壊群における鎮痛は，検定量はそれぞれ40mg/kgおよび80mg/kgであったが，連投前の(5mg/kg)鎮痛よりは大であったものの最大測定時間には達せず，破壊群においても耐性形成が認められた．朝夕2回の分割投与による体重の日内変動の逆転，連投による体温の日内変動の消失，依存状態におけるpentobarbital 45分間麻酔によるPcs値の日内変動の消失などは，対照群におけると同様に破壊群にも認められた．禁断による体重減少，Pcs値の上昇，血漿ACTH値の．L昇および副腎重量の増加も，対照群におけると同様に破壊群にも認められた．連投中および禁断時の種々の指標において，破壊群における依存の形成が明らかにされた．以上の結果は，鎮痛の発現にはNRGCが関与するが，耐性および依存形成におけるNRGCの関与は少ないことを示唆するものと考えられる．

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Tramadol is a weak opioid that produces analgesic effect via both the μ-opioid receptor (

) and non-opioid targets. Constipation is the most common opioid-related side effect in patients with cancer and non-cancer pain. However, the contribution of to tramadol-induced constipation is unclear. Therefore, we used naldemedine, a peripherally acting antagonist, and -knockout mice to investigate the involvement of peripheral in tramadol-induced constipation using a small intestinal transit model. A single dose of tramadol (3–100 mg/kg, per os (p.o.)) inhibited small intestinal transit dose-dependently in rats. Naldemedine (0.01–10 mg/kg, p.o.) blocked the inhibition of small intestinal transit induced by tramadol (30 mg/kg, p.o.) in rats. The transition rate increased dose-dependently over the range of naldemedine 0.01–0.3 mg/kg, and complete recovery was observed at 0.3–10 m/kg. Additionally, tramadol (30 and 100 mg/kg, subcutaneously (s.c.)) inhibited small intestinal transit in wild-type mice but not in -knockout mice. These results suggest that peripheral participates in tramadol-induced constipation.

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The antinociceptive effects of lappaconitine (LA) and morphine () when injected intracerebroventriculary (i.c.v.), intracisternally (i.cist.) or intrathecally (i.t.) were investigated in mice by use of the tail pinch, hot plate and acetic acid-induced writhing tests. In addition, the effects of naloxone (NLX) administered subcutaneously on the antinociceptive action of LA and were studied. LA and after i.c.v., i.cist. and i.t. injection produced dose-dependent antinociception. was more potent in the tail pinch and acetic acid-induced writhing tests by i.t. injection than by i.c.v. or i.cist. injection, but the potency in the hot plate test was independent of the injection site. On the other hand, like , LA was more potent after i.t. injection than after i.c.v. or o.cist. injection in the tail pinch and acetic acid-induced writhing test. Its antinociceptive action was less potent than that of . The antinociceptive actions of were antagonized by NLX (1mg/kg.s.c.) in every test and injection site, whereas the antinociceptive actions of LA were not inhibited, except for the antinociception on the tail pinch test, which was partially antagonized by NLX. It is suggested that LA mainly produced an NLX-resistant antinociceptive effect at the spinal site.

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Improving water flux through a zeolite membrane is important in reducing the cost of manufacturing such membranes. Water flux through a mordenite () zeolite membrane was increased by 84% by treating it with a novel ion beam irradiation technique that maintained high water permselectivity (1200). Os ions were accelerated in a cyclotron at 490 MeV, and a fluence of 3.0 × 10¹¹ ions cm^-2 was employed for treatment. A calculation using SRIM 2012 showed that the Os ion tracks at 490 MeV should be passed through the zeolite layer. In this study, ion tracks of approximately φ 8 nm were measured on the surface view of the transmission electron microscope (TEM) observations. The single gas permeation of H₂ and N₂ at room temperature was almost the same before and after irradiation treatment. The ion track pathways through the layer were water permselective assuming that all the permeation change before and after irradiation was due to the ion track paths.

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New μ-opioid receptor () agonists containing piperazine and homopiperazine moieties in the structures were synthesized and their affinities to and agonist potencies on were evaluated. Among the synthesized compounds, 4-[4-(2-methoxyphenyl)piperazin-1-yl]-N,N-dimethyl-2,2-diphenylbutanamide (20Aa) showed the highest affinity to the human expressed in Chinese hamster ovary (CHO)-K1 cells, and the highest agonist potency on the in isolated guinea-pig ileum preparation.

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Although opioid analgesics are indispensable in treating pain, these drugs are accompanied by life-threatening side effects. While clinically relevant opioid drugs target the µ opioid receptor (

), a heterodimer between the and the δ opioid receptor (DOR) has emerged as another target to develop safer analgesics. Although some heterodimer-preferring agonists have been reported so far, it is still difficult to activate the /DOR heterodimer selectively in the presence of or DOR monomers/homodimers. To gain insights to develop selective agonists for /DOR, herein we prepared analogs of CYM51010, one of the reported heterodimer-preferring agonists, and collected structure–activity relationship information. We found that the ethoxycarbonyl group was needed for the activity for the heterodimer, although this group could be substituted with functional groups with similar sizes, such as an ethoxycarbonyl group. As for the acetylaminophenyl group, not a type of substituent, but rather a substituent located at a specific position (para-position) was essential for the activity. Changing the linker length between the acetylaminophenyl group and the piperidine moiety also had deleterious effects on the activity. On the other hand, the substitution of the acetylamino group with a trifluoroacetylamino group and the substitution of the phenethyl group with a benzyl group diminished the activities for the monomers/homodimers while keeping the activity for /DOR, which enhanced the selectivity. Our findings herein will play an important role in developing selective agonists for /DOR and for elucidating the physiological roles of this heterodimer in analgesic processes and in the establishment of side effects.

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The high-silica mordenite zeolite () was synthesized by adding NaF as a fluoride source to the synthesis gel in the middle of crystallization process. The addition of NaF into the synthesis gel enhanced the nucleation and crystal growth of zeolite, and depressed the nucleation of beta zeolite (BEA). When NaF was added in the middle of crystallization process, the fluoride content and the Na/Al ratio markedly decreased although the crystallinity and the Si/Al ratio of as-synthesized zeolite were independent of the time at which NaF was added. The decrease in the fluoride content considerably improved the thermal stability of the as-synthesized zeolite.

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This study examined the relationship between the opioid tolerance induced by high-dose fentanyl and the expression of the mu-opioid receptor () using the loose sciatic nerve ligation in rats. Fentanyl was administered at a dose of 10 μg/kg (LF10 group, n=6) or 30 μg/kg (LF30 group, n=6) or saline (control; LS group, n=6) three times a week for four weeks. The mechanical paw withdrawal threshold (MPWT; von Frey test) was examined over 26 days. expression was detected in the dorsal root ganglia (DRG). The MPWT in the LS and LF30 groups was significantly lower than that of the LF10 group. The expression of in the DRG was higher in the LS and LF30 groups. The ratio of -positive neurons in the DRG was inversely correlated with the MPWT. In conclusion, the loss of the analgesic effect of high-dose fentanyl is associated with an increase in the -positive neurons in the DRG.

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It is known that μ opioid receptor () is located on the dendrite of striosomal medium-spiny (MS) projection neurons, and glutamatergic and non-glutamatergic presynaptic terminals innervating the MS neurons. The objective of this study was to investigate the -mediated effects on the excitatory and inhibitory synaptic transmission in the striatal striosome/matrix compartment. To identify the striosomes, we used a transgenic mouse strain (TH-GFP mouse) harbouring an eGFP reporter construct under the promoter of tyrosine hydroxylase, the rate-limiting enzyme for cathecolamine synthesis. Because dopaminergic neurons densely innervate the striosomal cells in early postnatal stage, a striosome is identified as a bright area under fluorescence microscope. Using corticostriatal slices obtained from TH-GFP mice (P14-P28), we made whole-cell recordings from MS neurons. DAMGO, an agonist of , significantly suppressed GABAergic IPSCs in the striosomes (-18.4%±3.6%), whereas DAMGO had no effects in the matrix (+3.1%±5.5%). On the contrary, the effect of DAMGO on EPSCs in the striosomes was identical to that in the matrix. The suppression of IPSCs was also observed in cholinergic interneurons located near the striosomes, therefore -mediated suppression of IPSCs might affect the release of endogenous acetylcholine. The -mediated effects on synaptic transmission may control the activity of local neural circuits in striosome/matrix compartment. [J Physiol Sci. 2007;57 Suppl:S8]

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Antinociceptive actions and effects of intracerebroventricular (i.c.v.) dynorphin-(1-13) (DYN) on morphine () analgesia and acute tolerance were studied in male Sprague-Dawley rats. Antinociceptive effect against hind paw pressure was produced by 30 μg of DYN, but not by 0.5-10 μg. Acetic acid writhing was inhibited dose-dependently by DYN at the doses of 2-30 μg, and the order of potency of the anti-writhing effect was β-endorphin > > DYN >> Met-enkephalin. The anti-writhing effect of DYN that was partially antagonized by naloxone at 10 mg/kg, s.c. in tolerant rats was the same as that in naive rats. The anti-writhing effect of i.c.v.- was increased synergistically by DYN. Continuous s.c. (6 mg/kg/hr) and i.c.v. (7.5 μg/rat/hr) infusion of produced antinociception against hind paw pressure, which reached maximum (MAX) and attenuated thereafter during infusion for 6 hr. The attenuation of antinociception was also produced during infusion combined with multiple i.c.v.-injection of DYN. The MAX and area under the anti-nociceptive curve during infusion was not affected by multiple injection of DYN, i.e., no effect of i.c.v.-DYN on the development of acute tolerance induced by s.c.- and i.c.v.-infusion was observed. In conclusion, the anti-writhing effect of i.c.v.-DYN might not be mediated via mu-receptors, although DYN increased the anti-writhing effect of i.c.v.- synergistically and the development of acute tolerance to (i.c.v., s.c.) was not affected by i.c.v.-DYN.

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腎機能障害を合併した終末期癌患者で, モルヒネによる癌疼痛治療を行なった3名を対象として, 血中モルヒネ, モルヒネ代謝物濃度を, 経時的に検討した. 腎機能障害を合併した終末期癌患者では, モルヒネ, モルヒネ代謝物とも上昇する. とりわけ, BUN, 血中クレアチニン値ともに上昇する高度腎機能障害では, モルヒネ代謝物の蓄積が顕著で, 予期せぬ副作用がみられる可能性があり, 血中モルヒネ, モルヒネ代謝物濃度を測定し, モルヒネ至適投与法を検討する必要がある.

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